In recent studies it has been shown that eel acetylcholinesterase (AChE, EC 3.1.1.7) previously inhibited with 1,3,2-dioxaphosphorinane 2-oxides undergoes spontaneous reactivation with a t.sub.1/2 =12 minutes at pH 7.0 in marked contrast to enzyme inhibited with O,O-diethylphosphoryl derivatives, see Ashani et al Biochemistry 11, 3518 (1972) and Ashani and Leader, Biochem.J. 177, 781 (1979).
The protection of mammals against poisoning by organo-phosphorus compounds by pretreatment with carbamates have been attributed to inhibition of acetylcholinesterase (AChE, EC 3.1.1.7) by forming labile carbamoyl-AChE conjugates. This inhibition prevents complete and irreversible phosphorylation and consequently enzyme activity is restored due to spontaneous decarbamoylation. The rate of AChE regeneration depends amongst others on the structure of the carbamoyl moiety and on the kinetic properties of the enzyme, see f. f. Gordon et al Toxicol and App. Pharmacol. 43, 207 (1978).
In addition, carbamates are commonly used for the treatment of diseases that are associated with cholinergic disorders, e.g. pyridostigmine bromide in Myasthenia Gravis, neostigmine methylsulphate in neurogenic bladder dysfunctions and physostigmine in brain disorders.
Carbamates of this type are rather toxic drugs and the maximum dosage which does not result in side-effects for compounds such as physostigmine sulfate and pyridostigmine iodide in guinea pigs is 0.1 mg/kg respectively.